The disclosure relates to a method and apparatus for forming semiconductor devices on a semiconductor wafer. More specifically, the disclosure relates to light up suppression in a substrate support during the formation of semiconductor devices.
Semiconductor processing systems are used to process substrates such as semiconductor wafers. Example processes that may be performed on such systems include, but not limited to, conductor etch, dielectric etch, atomic layer deposition, chemical vapor deposition, and/or other etch, deposition or cleaning processes. A substrate may be arranged on a substrate support, for example, a pedestal, an electrostatic chuck (ESC), in a processing chamber of the semiconductor processing system. A substrate support may include a ceramic layer with embedded heaters, high voltage electrodes and also a base plate bonded to the ceramic layer. A substrate support may further include helium distribution channels for supplying helium to the backside of a wafer to control the thermal conductivity between a substrate and a substrate support. Semiconductor processing systems may implement plasma processes (e.g., plasma etch processes) that require high RF power which will cause high voltages to appear at a substrate support. The increase in voltage applied across the substrate support may cause undesired effects such as arcing or gas light up in helium distribution channels and/or other cavities of the substrate support. Light up may damage the semiconductor devices and the processing chamber, create particle defects on the wafer, damage semi-conductor devices on a wafer, etc., thus increasing costs and equipment down time and decreasing product yield.